A new study has found that a boy in the UK was left blind due to a "junk food diet".
A case report published in the Annals of Internal Medicine, by researchers at the Bristol Eye Hospital, found that a 17-year-old went blind due to his diet of chips, white bread and sausages.
The boy's weight and height were described as being "average" and his BMI was normal.
He told doctors he didn't drink, smoke or take drugs.
The unnamed boy first reported to his GP aged 14, complaining of tiredness.
He was described at the time as being a "fussy eater" but he "was otherwise well and took no medications."
Tests found that he had anemia and low levels of b12 vitamins and he was treated with vitamin injections and was also give dietary advice.
The report revealed that the following year, the boy developed "sensorineural hearing loss" and he was referred to an otolaryngologist.
An MRI "showed no structural abnormalities" and he began to develop vision symptoms soon after.
Following two years of "progressive" vision loss, the study states that the 17-year-old was referred to a neuro-ophthalmologist.
It was determined that the teen had symptoms "consistent with optic neuropathy."
According to the research, nutritional optic neuropathy from "purely dietary causes" is "rare in developed countries."
The report said that the boy's "visual acuity was 20/200 bilaterally".
It adds: "The patient confessed that, since elementary school, he would not eat certain textures of food.
"He had a daily portion of fries from the local fish and chip shop and snacked on Pringles (Kellogg), white bread, processed ham slices, and sausage."
The report found that the boy had been suffering from avoidant-restrictive food intake disorder, which is "a relatively new diagnostic entity".
It is not driven by weight concerns but "with lack of interest in food, heightened sensitivity to food textures, and fear of the consequences of eating."
The boy was "prescribed nutritional supplements that corrected his deficiencies and was referred to mental health services for his eating disorder.
"His visual acuities stabilized but did not improve."
Dr Denize Atan, one of the report's authors, said: "The association between poor nutrition and vision has been established for a long time.
"I would hope most cases are picked up early and treated, but some clearly pass through the net and greater awareness of the condition would prevent that from happening again."
The report said that the boy's "history of treated vitamin B12 deficiency and low-normal vitamin B12 level likely contributed to the delayed diagnosis."
It concluded that "'Fussy eating' that is restricted to junk foods and causes multiple nutritional deficiencies is an eating disorder."
It added: "Nutritional optic neuropathy should be considered in any patient with unexplained vision symptoms and poor diet, regardless of BMI.
"It is important to note that nutritional optic neuropathy is potentially reversible if caught early. If left untreated, it leads to permanent blindness."